Heat dissipation structure and battery including the same

Abstract

[Problem] To provide a heat radiation structure and a battery that may adapt to various forms of a heat source, have excellent elastic deformation, have excellent heat radiation efficiency, improve the equalization of the heat radiation of each of a plurality of heat sources, and improve the productivity.　[Solution] The present invention relates to a heat radiation structure 1 and a battery, including: a plurality of heat radiation members 20; and a support plate 10 for supporting the plurality of heat radiation members 20, the heat radiation members 20 including a plurality of cushion members 22 having a hollow or solid shape, and heat conducting sheets 21 covering the outside surfaces of the cushion members 22, the support plate 10 including a plurality of trench parts 15 in a direction perpendicular to the longitudinal direction of the heat radiation members 20, the trench parts 15 being for supporting the heat radiation members 20, and each trench part 15 being a curved trench part that is open on the heat radiation member 20 side and recessed in the thickness direction, each trench part 15 being formed to have a curvature radius R2 larger than the curvature radius R1 of each heat radiation member 20 and a depth T smaller than the circle conversion diameter D of each heat radiation member 20.

Description

Cross-reference

[0001] This application claims priority based on Japanese Patent Application No. 2020-092967 filed in Japan on May 28, 2020, and the content described in the application is incorporated herein by reference. In addition, the content described in the patents, patent applications, and documents cited in this application is incorporated herein by reference.

Technical Field

[0002] The present invention relates to a heat dissipation structure and a battery including the same.

Background Art

[0003] The control systems of automobiles, aircraft, ships, or household or business-use electronic devices have become more precise and complex, and accordingly, the integration density of small electronic components on circuit boards has been continuously increasing. As a result, it is strongly desired to solve the problems of failure and shortened lifespan of electronic components due to heat generation around the circuit board.

[0004] In order to achieve rapid heat dissipation from a circuit board, conventionally, means such as forming the circuit board itself from a material with excellent heat dissipation properties, attaching a heat sink, or driving a cooling fan have been carried out singly or in combination. Among these, the method of forming the circuit board itself from a material with excellent heat dissipation properties, such as diamond, aluminum nitride (AlN), cubic boron nitride (cBN), etc., extremely increases the cost of the circuit board. In addition, the arrangement of a cooling fan causes problems such as failure of the rotating device called a fan, the necessity of maintenance for preventing failure, and difficulty in securing an installation space. On the other hand, heat dissipation fins are simple members that can increase the surface area and enhance heat dissipation by forming a large number of columnar or flat protruding portions using a metal with high thermal conductivity (for example, aluminum), and thus are widely used as heat dissipation components (see Patent Document 1).

[0005] By the way, currently, all over the world, there is an active movement to gradually convert conventional gasoline or diesel vehicles to electric vehicles for the purpose of reducing the burden on the global environment. In particular, in addition to European countries such as France, the Netherlands, and Germany, the popularization of electric vehicles is also progressing in China. For the popularization of electric vehicles, in addition to the development of high-performance batteries, the installation of a large number of charging stations is required. In particular, the technological development for enhancing the charge and discharge functions of lithium-based automotive batteries is important. It is well known that the above automotive battery cannot fully exhibit its charge and discharge functions at temperatures above 60 degrees Celsius. For this reason, similar to the circuit board described above, improving heat dissipation is also highly regarded in batteries.

[0006] To achieve rapid heat dissipation of the battery, a structure is adopted in which a water-cooling pipe is arranged in a metal casing made of a metal with excellent thermal conductivity such as aluminum, a large number of battery cells are arranged in the casing, and an adhesive rubber sheet is sandwiched between the battery cells and the bottom surface of the casing. In a battery with such a structure, the battery cells transfer heat to the casing through the rubber sheet and are effectively cooled by water cooling.

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0008] However, in the conventional battery as described above, since the rubber sheet has lower thermal conductivity compared to aluminum or graphite, it is difficult to efficiently transfer heat from the battery cell to the housing. Also, a method of sandwiching a spacer such as graphite instead of the rubber sheet can be considered, but since the lower surfaces of a plurality of battery cells are not flat but have steps, a gap is generated between the battery cell and the spacer, and the heat transfer efficiency decreases. As can be seen in such an example, since the battery cell can take various forms (including unevenness such as steps or a non-smooth surface state), there is an increasing demand for being adaptable to various forms of the battery cell and realizing high heat transfer efficiency. Also, in order to realize high heat transfer efficiency, it is desirable to uniformly dissipate heat from each of a large number of battery cells so that the temperatures of the large number of battery cells become uniform. Furthermore, a heat dissipation structure that returns to a shape close to the original shape when the battery cell is removed is desired. Also, improvement in the productivity of the heat dissipation structure is required. This applies not only to battery cells but also to other heat sources such as circuit boards, electronic components, or the electronic device body. Meeting such demands also contributes to the achievement of the applicant's sustainable development goal of "ensuring all people's access to affordable, reliable, and sustainable modern energy."

[0009] The present invention has been made in view of the above problems, and an object thereof is to provide a heat dissipation structure that can adapt to various forms of a heat source, is rich in elastic deformability, has excellent heat dissipation efficiency, enhances the uniformity of heat dissipation in each of a plurality of heat sources, and can improve productivity, and a battery including the same.

Means for Solving the Problems

[0010] (1) A heat dissipation structure according to an embodiment for achieving the above object includes a plurality of heat dissipation members for enhancing heat dissipation from a heat source, and a support plate for supporting the plurality of heat dissipation members. The heat dissipation member includes a plurality of cushion members having a hollow or solid shape, and a heat conduction sheet for transmitting heat from the heat source and covering the outer surface of the cushion member. The support plate includes a plurality of groove portions for supporting the heat dissipation members along a direction orthogonal to the longitudinal direction of the heat dissipation members. The groove portion is a curved groove portion that opens to the heat dissipation member side and is recessed in the thickness direction, and its radius of curvature is larger than the radius of curvature of the heat dissipation member, and its depth is formed to be smaller than the diameter of the heat dissipation member in terms of a circle. (2) In a heat dissipation structure according to another embodiment, preferably, the support plate may include at least one or more flow paths for flowing a cooling medium in the longitudinal direction. (3) In a heat dissipation structure according to another embodiment, preferably, the flow path may be a through passage penetrating the support plate. (4) In a heat dissipation structure according to another embodiment, preferably, the support plate may be a plate-shaped member made of metal. (5) In a heat dissipation structure according to another embodiment, preferably, the heat dissipation member may be a cylindrical member having a hollow portion along the longitudinal direction. (6) In a heat dissipation structure according to another embodiment, preferably, the cushion member is a cylindrical cushion member having the hollow portion in the longitudinal direction, and the heat conduction sheet may be wound spirally in the longitudinal direction around the outer surface of the cylindrical cushion member. (7) In a heat dissipation structure according to another embodiment, preferably, the heat conduction sheet and the cushion member may integrally have a form that spirally progresses in one direction. (8) A heat dissipation structure according to another embodiment preferably may have a heat conductive oil on the surface of the heat conduction sheet to enhance the heat conductivity from a heat source contacting the surface to the surface. (9) In the heat dissipation structure according to another embodiment, preferably, the thermally conductive oil may include silicone oil and a thermally conductive filler having a higher thermal conductivity than the silicone oil and composed of one or more of metal, ceramics, or carbon. (10) A battery according to an embodiment is a battery provided with one or more battery cells as heat sources in a housing, and includes any one of the above heat dissipation structures between the battery cells and the housing.

Advantages of the Invention

[0011] According to the present invention, it is possible to provide a heat dissipation structure that can adapt to various forms of heat sources, is rich in elastic deformability, has excellent heat dissipation efficiency, enhances the uniformity of heat dissipation in each of a plurality of heat sources, and can improve productivity, and a battery including the same.

Brief Description of the Drawings

[0012]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Description of Reference Numerals

[0013] 1, 1a... Heat dissipation structure, 10, 10a... Support plate, 15... Groove portion, 17, 17a... Through passage, 20, 20a... Heat dissipation member, 21... Heat conduction sheet, 22... Cushion member, 23, 23a... Hollow portion, 40... Battery, 41... Housing, 43... Flow path, 45... Cooling medium, 50... Battery cell (an example of a heat source), R1... Curvature radius of the heat dissipation member, R2... Curvature radius of the groove portion, T... Depth of the groove portion, D... Circular conversion diameter of the heat dissipation member.

Embodiments for Carrying Out the Invention

[0014] Next, each embodiment of the present invention will be described with reference to the drawings. Note that each of the embodiments described below does not limit the invention according to the claims, and not all of the elements and combinations thereof described in each embodiment are essential for the solution means of the present invention.

[0015] 1. Heat dissipation structure (First Embodiment) FIG. 1 shows a plan view of the heat dissipation structure according to the first embodiment. FIG. 2 shows a cross-sectional view taken along line A-A in FIG. 1 and an enlarged view of a part C thereof, respectively. FIG. 3 shows a cross-sectional view taken along line B-B in FIG. 1. In this embodiment, it is assumed that the heat source is disposed above the paper surface in FIGS. 2 and 3. The same applies to the subsequent embodiments. Also, in FIG. 1, the heat dissipation structure 1 includes 10 heat dissipation members 20, but the number of heat dissipation members 20 is not particularly limited. The same applies to the subsequent embodiments.

[0016] (1) Schematic configuration The heat dissipation structure 1 according to the first embodiment is a member including a plurality of heat dissipation members 20 that enhance heat dissipation from a heat source, and a support plate 10 that supports the plurality of heat dissipation members 20. The heat dissipation member 20 includes a plurality of cushion members 22 having a hollow or solid shape, and a heat conduction sheet 21 that is a sheet for transmitting heat from the heat source and covers the outer surface of the cushion member 22. The support plate 10 includes a plurality of groove portions 15 that support the heat dissipation member 20 along a direction (left - right direction in FIG. 1) orthogonal to the longitudinal direction of the heat dissipation member 20. The groove portion 15 is a curved groove portion that opens to the heat dissipation member 20 side and is recessed in the thickness direction. The groove portion 15 is formed such that its radius of curvature R2 is larger than the radius of curvature R1 of the heat dissipation member 20, and its depth T is smaller than the diameter D in terms of a circle of the heat dissipation member 20 (see FIG. 2). The heat dissipation member 20 may be referred to as a "heat conduction member" or a "heat transfer member". Note that the "radius of curvature" means the radius of a perfect circle that best approximates the degree of bending of the curve in the cross - section when the heat dissipation member 20 and the groove portion 15 are cut perpendicular to their longitudinal directions. Also, the "diameter in terms of a circle" means the diameter of a perfect circle having the same area as the area of the pipe cross - section when the heat dissipation member 20 is cut perpendicular to its longitudinal direction. These are the same in the following embodiments as well.

[0017] (2) Heat Conduction Sheet The heat conduction sheet 21 is preferably a sheet having a shape that progresses while being spirally wound. The heat conduction sheet 21 is preferably a sheet containing carbon, regardless of its constituent material, and more preferably a sheet composed of 90% by mass or more of carbon. For example, a graphite film formed by firing a resin can also be used for the heat conduction sheet 21. However, the heat conduction sheet 21 may be a sheet containing carbon and resin. In that case, the resin may be a synthetic fiber, and in that case, aramid fiber can be preferably used as the resin. "Carbon" as used in the present application is interpreted broadly to include any structure composed of carbon (element symbol: C) such as graphite, carbon black with lower crystallinity than graphite, diamond, and diamond-like carbon having a structure close to diamond. In this embodiment, the heat conduction sheet 21 can be a thin sheet obtained by curing a material in which graphite fibers or carbon particles are blended and dispersed in a resin. The heat conduction sheet 21 may be carbon fiber knitted in a mesh shape, and may be further blended or knitted. Note that various fillers such as graphite fibers, carbon particles, or carbon fibers are all included in the concept of carbon fillers.

[0018] When the heat conduction sheet 21 is a sheet including carbon and resin, the resin may exceed 50% by mass or be 50% by mass or less with respect to the total mass of the heat conduction sheet 21. That is, the heat conduction sheet 21 does not matter whether or not the resin is the main material as long as there is no major obstacle to heat conduction. As the resin, for example, a thermoplastic resin can be preferably used. As the thermoplastic resin, a resin having a high melting point such that it does not melt when conducting heat from a heat source is preferable. For example, polyphenylene sulfide (PPS), polyether ether ketone (PEEK), polyamideimide (PAI), aromatic polyamide (aramid fiber), etc. can be preferably mentioned. The resin is dispersed in the gaps between the carbon fillers, for example, in a particulate or fibrous form, in the state before the heat conduction sheet 21 is formed. In addition to the carbon filler and the resin, the heat conduction sheet 21 includes Al as a filler for further enhancing heat conduction. 2 O3 、AlN or diamond may be dispersed. Also, instead of the resin, an elastomer softer than the resin may be used. The heat conduction sheet 21 may also be a sheet containing metal and / or ceramics instead of or together with carbon as described above. As the metal, those with relatively high thermal conductivity such as aluminum, copper, and alloys containing at least one of them can be selected. Also, as the ceramics, 2 O 3 、AlN, cBN, hBN, etc. with relatively high thermal conductivity can be selected.

[0019] Whether the heat conduction sheet 21 has excellent conductivity or not is not a concern. The thermal conductivity of the heat conduction sheet 21 is preferably 10 W / mK or more. In this embodiment, the heat conduction sheet 21 is preferably a graphite film and is made of a material excellent in thermal conductivity and conductivity. The heat conduction sheet 21 is preferably a sheet excellent in curvature (or flexibility). There is no restriction on its thickness, but 0.02 - 3 mm is preferred, and 0.03 - 0.5 mm is more preferred. However, the thermal conductivity of the heat conduction sheet 21 decreases in the thickness direction as the thickness increases, but the heat transfer amount is larger for a thicker sheet. Therefore, it is preferable to determine the thickness in consideration of the strength, flexibility, and thermal conductivity of the sheet comprehensively.

[0020] (3) Cushion member The important functions of the cushion member 22 are ease of deformation and resilience. The resilience is due to elastic deformability. Ease of deformation is a characteristic necessary to follow the shape of the heat source. Especially in the case of a battery cell housed in a package that is easy to deform, such as a semi-solid substance like a lithium-ion battery or a content having a liquid-like property, the design dimensions are often irregular or the dimensional accuracy cannot be improved. Therefore, it is important to maintain the ease of deformation and the resilience for maintaining the follow-up force of the cushion member 22.

[0021] In this embodiment, the cushion member 22 is a cylindrical cushion member having a hollow portion 23 in the longitudinal direction of the heat dissipation member 20. The cushion member 22 improves the contact between the heat conduction sheet 21 and the heat source even when the heat source in contact with the heat conduction sheet 21 is not flat. Further, the hollow portion 23 facilitates the deformation of the cushion member 22, contributes to the weight reduction of the heat dissipation structure 1, and has a function of enhancing the contact between the heat conduction sheet 21 and the heat source. The cushion member 22 also functions as a protective member to prevent the heat conduction sheet 21 from being damaged or the like due to the load applied to the heat conduction sheet 21. In this embodiment, the cushion member 22 is a member having lower thermal conductivity than the heat conduction sheet 21. In this embodiment, although the hollow portion 23 is formed in a circular cross-sectional shape, the cross-sectional shape of the hollow portion 23 is not limited to a circle, and may be, for example, a polygon, an ellipse, a semi-circle, a substantially polygon with rounded vertices, or the like. Further, the hollow portion 23 may be composed of a plurality of hollow portions, such as two hollow portions having a semi-circular cross-sectional shape in which the circular cross-sectional shape is divided into two in the vertical or horizontal direction. Note that the cushion member 22 may have a solid shape without the hollow portion 23.

[0022] The cushion member 22 is preferably composed of a thermosetting elastomer such as silicone rubber, urethane rubber, isoprene rubber, ethylene propylene rubber, natural rubber, ethylene propylene diene rubber, nitrile rubber (NBR), or styrene butadiene rubber (SBR); a thermoplastic elastomer such as urethane-based, ester-based, styrene-based, olefin-based, butadiene-based, fluorine-based, or a composite thereof. The cushion member 22 is preferably composed of a material having high heat resistance such that it can maintain its form without melting or decomposing due to the heat transmitted through the heat conduction sheet 21. In this embodiment, the cushion member 22 is more preferably an impregnated silicone in a urethane-based elastomer or composed of silicone rubber. The cushion member 22 contains Al in the rubber to increase its thermal conductivity even slightly. 2 O 3It may also be configured by dispersing fillers typified by particles such as AlN, cBN, hBN, diamond, etc. The cushion member 22 may contain bubbles inside, or may not contain bubbles. Further, the "cushion member" means a member that is rich in flexibility and can be elastically deformed to be in close contact with the surface of the heat source, and in this sense, it can also be read as a "rubber-like elastic body". Furthermore, as a modification of the cushion member 22, instead of the above rubber-like elastic body, it can also be configured using metal. For example, the cushion member 22 can also be configured with spring steel. Furthermore, it is also possible to arrange a coil spring as the cushion member 22. Also, a metal spirally wound into a spring steel may be arranged on the annular back surface of the heat conduction sheet 21 as a cushion member. Also, the cushion member 22 can also be configured with a sponge or a solid (not a porous structure like a sponge) formed from resin, rubber, etc.

[0023] (4) Support plate The support plate 10 is preferably a plate-shaped member made of metal. The support plate 10 is more preferably composed of those with relatively high thermal conductivity, such as aluminum, copper, alloys containing at least one of them, etc. However, the support plate 10 may contain resin and / or ceramics, or may be composed of resin and / or ceramics instead of the above metal. Examples of the resin and ceramics include the same materials as the constituent materials of the aforementioned heat conduction sheet 21.

[0024] The support plate 10 preferably includes a support substrate 11 having a plurality of groove portions 15 for supporting the heat dissipation member 20, and a bottom plate 12. The support substrate 11 preferably includes a plurality of groove portions 15 disposed on a surface facing the heat source along a direction orthogonal to the longitudinal direction of the heat dissipation member 20 (the left-right direction in FIG. 2), and a plurality of notch portions 18 disposed on a surface facing the bottom plate 12 along a direction orthogonal to the longitudinal direction (see FIG. 7 described later). The groove portion 15 is a curved groove portion that opens to the heat dissipation member 20 side (heat source side) and is recessed in the thickness direction (the up-down direction in FIG. 2). The notch portion 18 is preferably a groove portion that opens to the bottom plate 12 side and is notched in a rectangular shape in the thickness direction (the up-down direction in FIG. 2). The notch portion 18 is preferably formed to penetrate in the longitudinal direction (the depth direction of the paper surface in FIG. 2). The bottom plate 12 is preferably a flat plate member that is joined to the surface of the support substrate 11 where the notch portion 18 is formed. When the support substrate 11 and the bottom plate 12 are joined, the support plate 10 forms a through passage 17 that penetrates the support plate 10 in the longitudinal direction by the notch portion 18 and the bottom plate 12. The through passage 17 serves as a flow path 43 for flowing the cooling medium 45 in the longitudinal direction. Note that the size and shape of the notch portion 18 are not particularly limited as long as they are at least large enough and shaped such that the cooling medium 45 can flow through. Also, the number of notch portions 18 provided in the heat dissipation structure 1 is not particularly limited. Further, the support plate 10 may be such that the support substrate 11 and the bottom plate 12 are integrally formed. Also, the cooling medium 45 may be read as a "cooling member" or a "cooling agent". The cooling medium 45 is not limited to cooling water and is interpreted to include organic solvents such as liquid nitrogen and ethanol. The cooling medium 45 is not necessarily a liquid under the circumstances in which it is used for cooling and may be a gas or a solid. Also, since the "support plate" is a plate member that transfers heat from the heat dissipation member 20 to the cooling medium to cool the heat source, it may be referred to as a "cooling plate".

[0025] The heat dissipation member 20 is crushed in the vertical direction, that is, in the direction toward the flow path 43 through which the cooling medium 45 flows from the heat source, under the pressure from the heat source. If the heat dissipation member 20 is hardly crushed, the adhesion between the heat conduction sheet 21 and the heat source or the like may be reduced. The thickness of the heat dissipation member 20 when compressed in the vertical direction, which is appropriate for reducing such a risk, is at least 80% of the pipe diameter (= diameter in terms of a circle: D) of the heat dissipation member 20. The groove portion 15 is formed such that its depth T is smaller than the diameter D of the heat dissipation member 20 in terms of a circle. The groove portion 15 is preferably formed such that its depth T is at least 80% (0.8D) or less of the pipe diameter of the heat dissipation member 20 (see the enlarged view of a part C in FIG. 2). In this embodiment, the groove portion 15 is formed such that its depth T is 80% (0.8D) of the pipe diameter of the heat dissipation member 20. Here, the depth T of the groove portion 15 is the length from the surface of the support substrate 11 facing the heat source to the bottom of the groove portion 15. By forming the groove portion 15 in this way, the heat source and the heat dissipation member 20 can be surely brought into contact with each other, and the heat dissipation member 20 can be compressed to an appropriate thickness when compressed at least in the above-described vertical direction.

[0026] Further, the groove portion 15 is formed such that its radius of curvature R2 is larger than the radius of curvature R1 (= 0.5D) of the heat dissipation member 20. By forming the groove portion 15 in this way, when the heat dissipation member 20 is pressed by the heat source and collapses, the heat dissipation member 20 can be deformed into a substantially elliptical shape along the curved surface of the groove portion 15 (see the enlarged view of a part C in FIG. 2). Therefore, the heat dissipation structure 1 has a larger contact area between the heat dissipation member 20 and the support plate 10 when the heat dissipation member 20 is pressed by the heat source and collapses, compared with, for example, the case where the radius of curvature R2 of the groove portion 15 is smaller than the radius of curvature R1 of the heat dissipation member 20 or the case where the support plate 10 does not include the groove portion 15. Also, it is preferable that the groove portion 15 is configured such that its length L2 in the longitudinal direction is longer than the length L1 in the longitudinal direction of the heat dissipation member 20 (see FIG. 3). By being configured in this way, the support plate 10 can surely support the heat dissipation member 20 even when the heat dissipation member 20 expands and contracts in its longitudinal direction due to the pressing from the heat source. However, the support plate 10 may be configured such that the length L2 in the longitudinal direction of the groove portion 15 is the same as the length L1 in the longitudinal direction of the heat dissipation member 20. Note that the number of groove portions 15 provided in the heat dissipation structure 1 is not particularly limited as long as it is at least the same as or more than the number of heat dissipation members 20. For example, it may be the same as the number of heat dissipation members 20 or more than the number of heat dissipation members 20.

[0027] (5) Thermal Conductive Oil The thermal conductive oil preferably includes silicone oil and a thermal conductive filler made of one or more of metal, ceramics, or carbon, which has higher thermal conductivity than silicone oil. The thermal conductive sheet 21 has microscopic gaps (holes or recesses). Usually, air exists in the gaps, which may have an adverse effect on the thermal conductivity. The thermal conductive oil fills the gaps and exists in place of the air, having the function of improving the thermal conductivity of the thermal conductive sheet 21.

[0028] The heat-conductive oil is provided on the surface of the heat-conductive sheet 21, at least on the surface where the heat source and the heat-conductive sheet 21 are in contact. In the present application, the "oil" of the heat-conductive oil refers to a non-water-soluble combustible substance that is liquid or semi-solid at normal temperature (any temperature in the range of 20 to 25 °C). Instead of the term "oil", "grease" or "wax" can also be used. The heat-conductive oil is an oil that does not hinder heat conduction when transferring heat from the heat source to the heat-conductive sheet 21. As the heat-conductive oil, hydrocarbon-based oil or silicone oil can be used. The heat-conductive oil preferably contains silicone oil and a heat-conductive filler having higher thermal conductivity than silicone oil and composed of one or more of metal, ceramics or carbon.

[0029] The silicone oil preferably consists of molecules having a linear structure with 2000 or less siloxane bonds. The silicone oil is roughly classified into straight silicone oil and modified silicone oil. Examples of straight silicone oil include dimethyl silicone oil, methylphenyl silicone oil, and methylhydrogen silicone oil. Examples of modified silicone oil include reactive silicone oil and non-reactive silicone oil. Reactive silicone oil includes various silicone oils such as amino-modified type, epoxy-modified type, carboxy-modified type, carbinol-modified type, methacryl-modified type, mercapto-modified type, and phenol-modified type. Non-reactive silicone oil includes various silicone oils such as polyether-modified type, methylstyryl-modified type, alkyl-modified type, higher fatty acid ester-modified type, hydrophilic special-modified type, higher fatty acid-containing type, and fluorine-modified type. Since the silicone oil is an oil excellent in heat resistance, cold resistance, viscosity stability, and thermal conductivity, it is particularly suitable as a heat-conductive oil to be applied to the surface of the heat-conductive sheet 21 and interposed between the heat source and the heat-conductive sheet 21.

[0030] The thermally conductive oil preferably contains, in addition to the oil component, a thermally conductive filler composed of one or more of metals, ceramics, or carbon. Examples of the metal include gold, silver, copper, aluminum, beryllium, tungsten, and the like. Examples of the ceramics include alumina, aluminum nitride, cubic boron nitride, hexagonal boron nitride, and the like. Examples of the carbon include diamond, graphite, diamond-like carbon, amorphous carbon, carbon nanotube, and the like.

[0031] The thermally conductive oil is preferably interposed not only between the heat source and the thermal conduction sheet 21 but also between the thermal conduction sheet 21 and the housing of the battery described later. The thermally conductive oil may be applied to the entire surface of the thermal conduction sheet 21 or a part of the thermal conduction sheet 21. The method of causing the thermally conductive oil to be present on the thermal conduction sheet 21 is not particularly limited and may be by any method such as spraying using a spray, coating using a brush or the like, or dipping the thermal conduction sheet 21 into the thermally conductive oil. Note that the thermally conductive oil is not an essential component for the heat dissipation structure 1 or the battery described later, but is an additional component that can be preferably provided. This also applies to the following embodiments.

[0032] The heat dissipation structure 1 is arranged on the support plate 10 along the direction orthogonal to its longitudinal direction in a state where a plurality of heat dissipation members 20 are supported by the groove portion 15. The groove portion 15 is a curved groove that opens on the heat dissipation member 20 side and is recessed in the thickness direction, and its radius of curvature R2 is larger than the radius of curvature R1 of the heat dissipation member 20, and its depth T is formed to be smaller than the diameter D in terms of circle of the heat dissipation member 20. Thereby, even when the lower end portions of a plurality of heat sources are not flat, the contact between the heat conduction sheet 21 and the lower end portions is improved. In order to achieve high heat transfer efficiency, it is desirable to dissipate heat uniformly from each of a large number of heat sources so that the temperature of each of the large number of heat sources becomes uniform. For that purpose, it is preferable to arrange the plurality of heat dissipation members 20 so that the number of heat dissipation members 20 in contact with each heat source is uniform. The heat dissipation structure 1 preferably sets the number and position of the groove portions 15 in the support plate 10 in consideration of the sizes of a large number of heat sources, and sets the number of the heat dissipation members 20. By designing the heat dissipation structure 1 in this way, the plurality of heat dissipation members 20 are positioned on the support plate 10. Therefore, the heat dissipation structure 1 can enhance the uniformity of heat dissipation in each of a large number of heat sources. Further, the heat dissipation structure 1 can be positioned by arranging the plurality of heat dissipation members 20 in the groove portions 15 of the support plate 10 without connecting the plurality of heat dissipation members 20 with a thread or the like, and the productivity can be improved. Further, since the heat dissipation structure 1 has a structure in which the heat conduction sheet 21 is spirally wound around the outer surface of the cushion member 22 for each heat dissipation member 20, the deformation of the cushion member 22 is not excessively restricted. Note that the plurality of heat dissipation members 20 are not limited to being arranged at equal intervals in the distance between the heat dissipation members 20. That is, the plurality of groove portions 15 are not limited to being arranged at equal intervals in the distance of the groove portion 15 winding.

[0033] (Second Embodiment) Next, the heat dissipation structure according to the second embodiment will be described. The same reference numerals are given to the parts common to the previous embodiment, and the overlapping description will be omitted.

[0034] FIG. 4 shows the heat dissipation structure according to the second embodiment in a view regarded as the same as FIG. 2.

[0035] The heat dissipation structure 1a according to the second embodiment has a structure similar to that of the heat dissipation structure 1 according to the first embodiment, but is different from the heat dissipation structure 1 according to the first embodiment in that it includes a support plate 10a instead of the support plate 10. Since the configuration of the heat dissipation structure 1a other than the support plate 10a is the same as that of the heat dissipation structure 1 according to the first embodiment, detailed description thereof will be omitted.

[0036] The support plate 10a is preferably a member manufactured by integral molding, unlike the support plate 10 of the first embodiment which is manufactured by joining the support substrate 11 and the bottom plate 12. The support plate 10a includes a plurality of groove portions 15 disposed on a surface facing the heat source along a direction orthogonal to the longitudinal direction of the heat dissipation member 20 (the left-right direction in FIG. 4), and a through passage 17a disposed along a direction orthogonal to the longitudinal direction. The through passage 17a is formed to penetrate the support plate 10a in the longitudinal direction (the depth direction of the paper surface in FIG. 4). Similar to the through passage 17 of the first embodiment, the through passage 17a serves as a flow path 43 for flowing the cooling medium 45 in the longitudinal direction. In this embodiment, the through passage 17a is formed with a circular cross-section, but the cross-sectional shape of the through passage 17a is not limited to a circle, and may be, for example, a polygon, an ellipse, a semi-circle, a substantially polygon with rounded vertices, etc. Further, the through passage 17a may be composed of a plurality of through passages, such as two through passages with a semi-circular cross-section where the circular cross-section is divided into two in the up-down or left-right direction. Also, the size and position of the through passage 17a are not particularly restricted as long as they are at least of a size and position capable of flowing the cooling medium 45. Also, the number of through passages 17a provided in the heat dissipation structure 1 is not particularly restricted. Since the material of the support plate 10a and the configuration of the groove portions 15 are the same as those of the support plate 10 of the first embodiment, detailed description thereof will be omitted. The heat dissipation structure 1a configured in this way also exhibits the same effects as the first embodiment.

[0037] 2. Manufacturing Method of Heat Dissipation Structure Next, an example of a suitable manufacturing method of the heat dissipation structure 1 according to the first embodiment will be described.

[0038] FIG. 5 shows a diagram for explaining the manufacturing process of the heat dissipation member constituting the heat dissipation structure. FIG. 6 shows a diagram for explaining the manufacturing process of the support plate constituting the heat dissipation structure according to the first embodiment.

[0039] First, an example of a suitable manufacturing method for the heat dissipation member 20 constituting the heat dissipation structure 1 will be described. First, a cushion member 22 having a hollow portion 23 is molded (see a in FIG. 5). Next, an adhesive is applied to the outer surface of the cushion member 22. Next, after the strip-shaped heat conduction sheet 21 is spirally wound around the outer surface of the cushion member 22, if there is a portion where the heat conduction sheet 21 protrudes from both ends of the cushion member 22, the protruding portion is cut or the entire cushion member 22 is cut (see b and c in FIG. 5). Finally, a heat conductive oil is applied to the surface of the heat conduction sheet 21. It is also possible to fix the cushion member 22 and the heat conduction sheet 21 without interposing an adhesive therebetween. In that case, a cushion member 22 in a state before complete curing is prepared, and the strip-shaped heat conduction sheet 21 is wound around its outer surface. Then, the cushion member 22 is heated to be completely cured, and the heat conduction sheet 21 is fixed to the outer surface of the cushion member 22.

[0040] The cutting step of cutting the portion where the heat conduction sheet 21 protrudes from both ends of the cushion member 22 and the coating step of applying the heat conductive oil are not limited to being performed at the above-described timing. For example, the cutting step may be performed after the coating step.

[0041] Next, an example of a suitable manufacturing method for the support plate 10 constituting the heat dissipation structure 1 will be described. First, a support substrate 11 and a bottom plate 12 are prepared (refer to d in FIG. 6). The support substrate 11 is preferably manufactured by cutting, extrusion molding, or the like. The support substrate 11 is formed such that the radius of curvature R2 of the groove portion 15 is larger than the radius of curvature R1 of the heat dissipation member 20, and the depth T of the groove portion 15 is smaller than the diameter D in terms of a circle of the heat dissipation member 20 (refer to FIG. 2). Next, the support plate 10 is manufactured by joining the support substrate 11 and the bottom plate 12 by welding or the like (refer to e in FIG. 6). At this time, the support substrate 11 and the bottom plate 12 are joined so that the notch portion 18 provided in the support substrate 11 and the bottom plate 12 face each other.

[0042] The heat dissipation structure 1 is manufactured by arranging a plurality of heat dissipation members 20 manufactured by the above-described manufacturing method in a plurality of groove portions 15 provided in the support plate 10 manufactured by the above-described manufacturing method. In this case, the plurality of heat dissipation members 20 are preferably arranged in the respective groove portions 15 by rolling on the inclined surface from the upstream side of the inclined surface so that the surface of the support plate 10 having the groove 15 is inclined obliquely with respect to the horizontal plane. In the heat dissipation structure 1 manufactured in this way, since the plurality of heat dissipation members 20 can be arranged in the plurality of groove portions 15 simply by rolling on the inclined surface of the support plate 10 fixed to be inclined obliquely, the plurality of heat dissipation members 20 can be easily positioned on the support plate 10 without connecting them with a thread or the like, and the productivity can be improved. Note that, before joining the support substrate 11 and the bottom plate 12, the plurality of heat dissipation members 20 may be arranged on the support substrate 11. In this case, the heat dissipation structure 1 is manufactured by joining the support substrate 11 on which the plurality of heat dissipation members 20 are arranged and the bottom plate 12.

[0043] The heat dissipation structure 1a according to the second embodiment is manufactured by arranging a plurality of heat dissipation members 20 manufactured by the above-described manufacturing method in a plurality of groove portions 15 provided in a support plate 10a manufactured by cutting, extrusion molding, or the like. In this case, the plurality of heat dissipation members 20 are fixed such that the surface of the support plate 10a having the grooves 15 is inclined obliquely with respect to the horizontal plane, and roll from the upstream side of the obliquely inclined slope over the slope, so as to be arranged in each of the plurality of groove portions 15 preferably. Similar to the support plate 10, the support plate 10a is formed such that the radius of curvature R2 of the groove portion 15 is larger than the radius of curvature R1 of the heat dissipation member 20, and the depth T of the groove portion 15 is smaller than the diameter D in terms of a circle of the heat dissipation member 20. The heat dissipation structure 1a manufactured in this way can also easily position the plurality of heat dissipation members 20 on the support plate 10a without connecting the plurality of heat dissipation members 20 with a thread or the like, and can improve productivity.

[0044] An example of a preferred manufacturing method of a modified example of the heat dissipation structure 1 will be described. In this modified example, since it is manufactured by the same manufacturing method as the above-described heat dissipation structure 1 except that the heat dissipation member 20 constituting the heat dissipation structure 1 is replaced with a heat dissipation member 20a, a detailed description thereof will be omitted. Hereinafter, a preferred manufacturing method of the heat dissipation member 20a will be described.

[0045] FIG. 7 shows a diagram for explaining a preferred manufacturing process of a modified example of the heat dissipation member constituting the heat dissipation structure.

[0046] First, a strip-shaped laminated sheet 28 is manufactured. In the manufacture of the strip-shaped laminated sheet 28, the heat conduction sheet 21 and the cushion member 22 are preferably fixed with an adhesive. Next, the strip-shaped laminated sheet 28 is advanced in one direction while being spirally wound to manufacture a long heat dissipation member 20a. As a manufacturing method in which no adhesive is interposed between the heat conduction sheet 21 and the cushion member 22, the following methods can be exemplified. For example, the heat conduction sheet 21 is pasted on the cushion member 22 in a non-cured state in which the cushion member 22 is not completely cured. Thereafter, the cushion member 22 is completely cured by heating.

[0047] After the strip-shaped laminated sheet 28 is spirally wound, both ends of the laminated sheet 28 may be cut to adjust the shape. Finally, a heat-conductive oil is applied to the surface of the heat-conductive sheet 21. The heat-radiating member 20a includes a hollow portion 23a penetrating in its longitudinal direction. Different from the heat-radiating member 20 in the above-described embodiment, the hollow portion 23a also penetrates in the direction of the outer surface of the heat-radiating member 20a. In this way, the cushion member 22 is disposed inside the heat-conductive sheet 21, and the heat-conductive sheet 21 and the cushion member 22 integrally have a form that spirally advances in one direction. Since the entire heat-radiating member 20a is spiral, it is easier to expand and contract in the longitudinal direction of the heat-radiating member 20a than the above-described heat-radiating member 20.

[0048] Note that the heat-radiating structure 1a can also include the heat-radiating member 20a instead of the heat-radiating member 20. In this case, the heat-radiating structure 1a can be manufactured by the same manufacturing method as the above-described heat-radiating structure 1a except that the heat-radiating member 20 is replaced with the heat-radiating member 20a.

[0049] 3. Battery Next, the battery according to the present embodiment will be described.

[0050] FIG. 8 shows a longitudinal sectional view of a battery including a heat-radiating structure. Here, the "longitudinal sectional view" means a view obtained by vertically cutting from the upper opening surface to the bottom inside the housing of the battery.

[0051] In this embodiment, the battery 40 is, for example, a battery for an electric vehicle and includes a number of battery cells 50. The battery 40 includes a bottomed housing 41 that opens on one side. The housing 41 is preferably made of aluminum or an aluminum-based alloy. The battery cells 50 are arranged inside the housing 41 at 44. Above the battery cells 50, electrodes (not shown) are provided to protrude. The plurality of battery cells 50 are preferably arranged in the housing 41 and are adapted to be in close contact with each other by applying a force in the compressing direction using screws or the like from both sides thereof (not shown). The battery cells 50 are arranged in the housing 41 so as to sandwich the heat dissipation structure 1 between the bottom 42 of the housing 41. On the bottom 42 side of the heat dissipation structure 1, a flow path 43 (through passage 17) for flowing cooling water, which is an example of the cooling medium 45, is provided.

[0052] The battery 40 includes the battery cells 50 as one or two or more heat sources in the housing 41. The plurality of heat dissipation members 20 provided in the heat dissipation structure 1 are interposed between the battery cells 50 and the cooling medium 45. In the battery 40 having such a structure, the battery cells 50 transfer heat to the cooling medium 45 flowing through the flow path 43 (through passage 17) through the heat dissipation members 20, and heat is effectively removed by water cooling.

[0053] With the battery cell 50 set inside the housing 41 (see Fig. 8), the heat dissipation structure 1 is compressed in the thickness direction of the heat dissipation structure 1 between the battery cell 50 and the bottom portion 42. As a result, heat from the battery cell 50 is more likely to be transmitted to the heat conduction sheet 21, the support plate 10, the flow path 43, and the cooling medium 45. Further, when the heat dissipation structure 1 is compressed in its thickness direction by the battery cell 50, the heat dissipation structure 1 is compressed until the length in the thickness direction of the heat dissipation member 20 reaches the depth T of the groove portion 15. That is, the heat dissipation member 20 is not compressed to a position where the length in its thickness direction becomes smaller than the depth T of the groove portion 15. For this reason, even if the heat dissipation member 20 is compressed in the thickness direction (vertical direction) by the pressing from the battery cell 50, it is possible to prevent the battery cell 50 from contacting the support plate 10 and the heat dissipation member 20 from being compressed more than the depth T of the groove portion 15. The depth T of the groove portion 15 is preferably 80% of the thickness (0.8D) of the heat dissipation member 20 in terms of the diameter D in circular conversion. Further, since the heat dissipation structure 1 includes the support plate 10, an operator can hold the support plate 10 and attach the heat dissipation structure 1 to the battery 40, improving workability. Note that the battery 40 may include the above-described heat dissipation structure 1a instead of the heat dissipation structure 1.

[0054] 4. Other Embodiments As described above, the preferred embodiments of the present invention have been described, but the present invention is not limited to these and can be implemented with various modifications.

[0055] Fig. 9 shows a cross-sectional view when placed horizontally so that the side surface of the battery cell contacts the heat dissipation structure, a partially enlarged view thereof, and a partial cross-sectional view when the battery cell expands during charge and discharge, respectively.

[0056] In the above-described first embodiment, the situation where the battery cell 50 is placed vertically and the heat dissipation structure 1 is brought into contact with the lower end thereof has been described. However, the arrangement form of the battery cell 50 is not limited to this. As shown in FIG. 9, the battery cell 50 may be arranged such that the side surface of the battery cell 50 is brought into contact with each of the heat dissipation members 20, 20a of the heat dissipation structure 1. The battery cell 50 increases in temperature during charging and discharging. If the container of the battery cell 50 itself is formed of a material rich in flexibility, the side surface of the battery cell 50 in particular may bulge. Even in such a case, as shown in FIG. 9, since each of the heat dissipation members 20, 20a constituting the heat dissipation structure 1 can be deformed in accordance with the shape of the outer surface of the battery cell 50, high heat dissipation performance can be maintained even during charging and discharging. Similarly, also in the above-described second embodiment, the battery cell 50 may be arranged such that the side surface of the battery cell 50 is brought into contact with each of the heat dissipation members 20, 20a of the heat dissipation structure 1a.

[0057] Further, the support plates 10, 10a may be formed with one or more positioning holes through which positioning pins provided on the housing 41 (such as the bottom portion 42) of the battery 40 can be inserted. The positioning holes are holes through which the positioning pins protruding from the bottom portion 42 of the battery 40 can be inserted. By inserting the positioning pins into the positioning holes, positioning between the battery 40 and the heat dissipation structures 1, 1a becomes easy. Note that the shapes and positions of the positioning holes and the positioning pins are not particularly restricted.

[0058] Also, in the above-described first embodiment, the support plate 10 was composed of the support substrate 11 and the bottom plate 12. However, the support plate 10 may not include the bottom plate 12. That is, the support plate 10 may be composed only of the support substrate 11. In this case, when the support plate 10 is installed on the battery 40, the support plate 10 may be installed such that the surface on the side of the notch portion 18 of the support plate 10 is placed on the bottom portion 42 of the housing 41. Thereby, a flow path 43 through which the cooling medium 45 flows in the longitudinal direction can be formed by the notch portion 18 and the bottom portion 42.

[0059] Further, the support plates 10, 10a are not particularly restricted in their form, and as long as they are provided with a plurality of groove portions 15 for supporting at least a plurality of heat dissipation members 20, 20a along a direction orthogonal to the longitudinal direction of the heat dissipation members 20, 20a, for example, they may not be provided with through passages 17, 17a. In this case, it is preferable that the battery 40 is provided with one or a plurality of water cooling pipes 43 for flowing a cooling medium 45 at the bottom 42 of the housing 41.

[0060] Further, the heat dissipation member 20 may not have a hollow portion 23 formed in the cushion member 22. In that case, the heat dissipation member 20 has a configuration in which the cushion member 22 is filled in the hollow portion of the spiral heat conduction sheet 21. The hollow portion may not be formed in the cushion member 22 as long as it is formed by at least the winding structure of the heat conduction sheet 21 among the heat conduction sheet 21 and the cushion member 22.

[0061] Further, the heat conduction sheet 21 provided in the heat dissipation member 20 does not have to be in a shape that spirally winds as long as it covers at least the outer surface of the cushion member 22. The heat dissipation member 20 may be, for example, in a form in which the outer surface of the cushion member 22 is covered with a single flat heat conduction sheet 21.

[0062] Further, the spiral cushion member 22 in the heat dissipation member 20a is not limited to be the same as the width of the heat conduction sheet 21, and may be larger or smaller than the width of the heat conduction sheet 21.

[0063] Further, the heat source includes not only the battery cell 50 but also all objects that generate heat, such as a circuit board and an electronic device body. For example, the heat source may be electronic components such as a capacitor and an IC chip. Similarly, the cooling medium 45 may be not only cooling water but also an organic solvent, liquid nitrogen, or a cooling gas. Further, the heat dissipation structures 1, 1a may be arranged in structures other than the battery 40, for example, electronic devices, household appliances, power generation devices, etc.

[0064] In addition, the plurality of components of each of the above-described embodiments can be freely combined, except when they cannot be combined with each other. For example, the heat dissipation structure 1a may be provided in the battery 40.

Industrial Applicability

[0065] The heat conduction member according to the present invention can be used in various electronic devices such as automobiles, industrial robots, power generation devices, personal computers, and household electrical appliances, in addition to automotive batteries. Further, the battery according to the present invention can be used not only for automotive batteries but also for rechargeable household batteries and batteries for electronic devices such as personal computers.

Claims

1. A heat dissipation structure including a plurality of heat dissipation members for enhancing heat dissipation from a heat source and a support plate for supporting the plurality of heat dissipation members, The heat dissipation member is A plurality of cushion members having a hollow or solid shape; a heat conductive sheet for transmitting heat from the heat source, the heat conductive sheet covering an outer surface of the cushion member; Equipped with the support plate includes a plurality of grooves extending along a direction perpendicular to a longitudinal direction of the heat dissipation member, the grooves supporting the heat dissipation member being arranged in the direction perpendicular to the longitudinal direction of the heat dissipation member; The heat dissipation structure is characterized in that the groove portion is a curved groove portion that opens toward the heat dissipation member and is recessed in the thickness direction, and is formed so that the radius of curvature is larger than the radius of curvature of the heat dissipation member and the depth is smaller than the circular equivalent diameter of the heat dissipation member.

2. The heat dissipation structure according to claim 1 , wherein the support plate has at least one flow passage for flowing a cooling medium in the longitudinal direction.

3. The heat dissipation structure according to claim 2 , wherein the flow passage is a through passage penetrating the support plate.

4. 4. The heat dissipation structure according to claim 1, wherein the support plate is a plate-like member made of metal.

5. The heat dissipation structure according to claim 1 , wherein the heat dissipation member is a tubular member having a hollow portion along the longitudinal direction.

6. the cushion member is a cylindrical cushion member having the hollow portion in the longitudinal direction, 6. The heat dissipation structure according to claim 5, wherein the heat conductive sheet is spirally wound around an outer surface of the cylindrical cushion member in the longitudinal direction.

7. The heat dissipation structure according to claim 5 , wherein the heat conductive sheet and the cushion member are integrally formed in a spiral shape progressing in one direction.

8. 8. The heat dissipation structure according to claim 1, further comprising a heat conductive oil on a surface of the heat conductive sheet for increasing thermal conductivity from a heat source in contact with the surface to the surface.

9. 9. The heat dissipation structure according to claim 8, wherein the thermally conductive oil contains silicone oil and a thermally conductive filler having a higher thermal conductivity than the silicone oil and made of one or more of metal, ceramics, and carbon.

10. A battery having one or more battery cells as heat sources within a housing, the battery comprising a heat dissipation structure according to claim 1 between the battery cells and the housing.

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